1. Field of the Invention
The invention relates to field-effect transistors, and more particularly, the use of additives to increase the performance of single-component polymer field-effect transistors.
2. Description of the Related Art
(Note: This application references a number of different publications as indicated throughout the specification by one or more reference numbers as superscripts x. A list of these different publications ordered according to these reference numbers can be found below in the section entitled “References.” Each of these publications is incorporated by reference herein.)
Recently, solution processed polymer field-effect transistors (FETs) have been shown to give saturation mobilities in the order of 10−1-100 cm2/Vs1. These mobilities make polymer field-effect transistor systems competitive with amorphous silicon, and may allow for the fabrication of high speed CMOS circuitry 2. Processing of organic bulk heterojunction solar cells (BHJ-OSCs) with the addition of a small percent of processing additives has become a widespread method for helping to improve the overall performance of devices 3. It has been postulated that addition of these processing additives helps to improve bulk organization in the bulk heterojunction, leading to a significant increase in all device properties such as fill factor, open-circuit voltage, and short-circuit current.
For organic FETs, the active layer-gate dielectric interface plays the biggest role in determining the overall device characteristics since the conduction pathway lays in a zone only several nanometers adjacent to the active layer-dielectric interface 4. For solution-processed organic FETs, processing conditions can significantly influence the organization of individual molecules or polymer chains on the gate dielectric5. Until now, choice of gate dielectric (i.e. polymer dielectric or silicon dioxide SiO2), gate dielectric passivation (i.e. hexamethyldisilazane or octytrichlorosilane treatment), solvent choice, and post-processing annealing are the techniques which are currently available to help optimize a given material's performance.